Algae general characters and classification
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This document discusses the classification and characteristics of algae. It describes the three main groups of algae - Chlorophyceae (green algae), Phaeophyceae (brown algae) and Rhodophyceae (red algae) - based on their dominant pigments, cell structure and life cycles. Key aspects covered include the photosynthetic pigments and organelles of each group, their reproductive mechanisms, importance as food sources, and commercial uses of substances extracted from them like agar and alginates.
Algae general characters and classification
- 1. ALGAE GENERAL CHARACTERS AND CLASSIFICATION
- 2. CHARACTERISTICS OF ALGAE CLASSIFICATION BASED ON PIGMENTS CHLOROPHYCEAE PHAEOPHYCEAE RHODOPHYCEAE
- 3. CHARACTERISTICS OF ALGAE AQUATIC AUTROPHIC MODE OF NUTRITION CHLOROPHYLL UNICELLULAR SEX ORGAN INDEPENDENT GAMETOPHTIC AND SPOROPHTIC PHASE GAMETOPHYTIC PHASE IS DOMINANT
- 4. PIGMENT All algae contain chlorophyll pigment A Chlorophyll A and B (all green algae and Euglena) Chlorophyll A and C (Brown algae) Chlorophyll A, Phycoerythrin and Phycocyanin (Red algae)
- 5. CLASSIFICATION OF ALGAE Based on Photosynthetic pigment, stored food and cell wall composition Chlorophyceae Phaeophyceae Rhodophyceae
- 6. Source: Pininterest, Landcare research,Biology educare,
- 7. Chlorophyceae (Green Algae) Green color (Dominant chlorophyll a and B Carotenoids are also present Plant body is thallus Unicellular- eg: Chlamydomonas Colonial- eg: Volvox sp. Filamentous- eg: Spirogyra Source:Spirogyra- QS study
- 8. Chlorophyceae (Green Algae) Chlorophylls and Carotenoids are localized in Chloroplast Chloroplast are of different shapes: 1.Discoid 2.Plate –like 3.Reticulate (Oedogomium) 4.Cup Shaped ( Chlamydomonas) 5. Spiral or ribbon (Spirogyra) Source:Spirogyra- Brittannica
- 9. Chlorophyceae (Green Algae) Chlorophylls contain roughly spherical body called pyrenoid. Pyrenoids are absent in other members of the plant kingsom. Pyrenoids act as a centre of carbon-di- oxide fixation to increase the efficiency of photosynthesis Reserve food material is : mostly starch around pyrenoids Sometimes oil droplets. Source:Spirogyra- Pininterest, Science direct
- 10. Chlorophyceae (Green Algae) Algae in spacecrafts!!! Algae Chlorella sp. are used: To provide oxygen for the astronauts To consume the carbon di oxide exhaled by them Potential source of food and energy Source:: Spirogyra- Algal research supply Reserve food material is : mostly starch around pyrenoids Sometimes oil droplets.
- 11. Chlorophyceae (Green Algae) Reproduction Vegetative Fragmentation Asexual Zoospores Sexual Fusion of Gametes Isogamous Anisogamous :eg- chlamydomonous Oogamous: eg: Volvox Source: Zoospore:- Wikepedia, Twitter
- 13. PHAEOPHYCEAE- Brown algae ECTOCARPUS SARGASSUM DICTYOTA lAMINARIA FUCUS Source: wikepedia, Seaweed, ,alibaba
- 14. PHAEOPHYCEAE- Brown algae Pigments The brown color is due to the dominance of fucoxanthin. 1. Other pigments are chlorophyll a, c and xanthophylls 2. They vary in color from olive green to various shades of brown 3. They are found in mainly in marine habitats 4. They don’t have unicellular members in this class
- 15. PHAEOPHYCEAE- Brown algae Pigments They show great variation in size and form Source: wikepedia, Biodiversity of central coast, All posters.com. ECTOCARPUS MACROCYSTIS LAMINARIA
- 16. LUMINARIA THALLUS STRUCTURE Hold fast helps in anchor Stipe: Has strengthening tissues and tube like cells to transport the food Blade: Phtotosynthetic organ PHAEOPHYCEAE Brown algae LAMINARIA Source: Meida store house, fiser man voice Macrocystis have Pneumatocysts
- 17. PHAEOPHYCEAE Brown algae Cell wall of their cells is covered by a gummy or gelatinous coating of algin or alginic acid. It is a water retaining material so that the algal cell will not dry up during low tide. Alginic acid is extracted commercially and used as an industrial thickening agent in food The reserve food are stored as complex carbohydrate such as laminarin and as a mannitol Porphyra , Laminaria and Sargassum are used as food.
- 18. PHAEOPHYCEAE Brown Algae Reproduction Vegetative Fragmentation Asexual Zoospores Sexual Fusion of Gametes Isogamous Anisogamous :eg- chlamydomonous Oogamous: eg: Volvox Source: Zoospore:- Wikepedia, Twitter
- 20. Rhodophyceae- Red algae Polysiphonia Porphyra Source: Pininterest, ,UCMP, Berkeley, Eat the weed. Gelidium Gracilaria
- 21. Red colour is due to the predominace r- phycoerythrin Other pigments present: chlorophylla, d, carotenoids and phycocyanin Majority of the red algae are marine with greater concentrations found in the warmer areas They occurs in both weLl lighted regions close to the surface of water. Pigments RHODOPHYCEAE- RED ALGAE
- 22. Deep water plants have more red pigments, while those in the intertidal may be reddish brown, yellowish or almost black. Pigments RHODOPHYCEAE- RED ALGAE Hypnea spicifera Source: South African Seaweeds - south coast
- 23. Most of the red algae are multicellular Many red algae are filamentous and have heterotrichous thallus Hetero= different trichous-= trichome or filament Heterotrichous means the presence of more than one type of filament Thallus RHODOPHYCEAE- RED ALGAE Chondracanthus corymbiferus Kappaphycus
- 24. Heterotrichous thallus consists of two system: a basal prostrate system erect branched upright system The food is stored as floridean starch The grain of floridean are found in the cytoplasm. Thallus RHODOPHYCEAE- RED ALGAE Source: pickuki.com Polysiphonia
- 25. RHODOPHYCEAE- RED ALGAE Reproduction Vegetative Fragmentation Asexual Zoospores Sexual Fusion of Gametes Isogamous Anisogamous :eg- chlamydomonous Oogamous: eg: Volvox Source: Zoospore:- Wikepedia, Twitter
- 26. Life cycle RHODOPHYCEAE- RED ALGAE Source: VCbio
- 27. Uses of Red algae Agar: a jelly like substance obtained from Gelidium and Gracilaria Carrageenans, gelatinous extract of the Chondrus crispus are widely used in the food industry. Sushi : Japanese food Nori Japanese name for edible seaweed species of the red algae of genus Pyropia
- 28. Algae- General Characteristics They are Chlorophyll bearing , simple thalloid, autotrophic and mainly aquatic organism They occur in a variety of other habitats Their form and size are highly variable They reproduce by Vegetative , Asexual and Sexual Method Vegetative- Fragmentation Asexual- by different types of spores Sexual Method- fusion of male and female gametes
- 29. Algae- General Characteristics Algae are useful to man in a variety of ways Atleast a half of the total Carbon di oxide on earth is carried out by algae through photosynthesis They form the basis of the food cycle of all aquatic animals Nearly 70 species of marine algae are used as food Water holding substances like algin obtained from brown algae, agar and carrageenan obtained from red algae are commercial importance Chlorella is use in spacetravel